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Abstract:

An organic material production system using biomass material includes: a
hydrothermal decomposition apparatus (13) that causes the biomass
material (11) and hot compressed water (12) to countercurrently contact
with each other and undergo hydrothermal decomposition, and that
transfers a lignin component and a hemicellulose component into the hot
compressed water, so as to separate the lignin component and the
hemicellulose component from a biomass solid residue; a cellulose
enzymatic saccharification device (17) that treats, with an enzyme,
cellulose in the biomass solid residue, so as to enzymatically saccharify
the cellulose to a first sugar solution containing hexose; an alcohol
fermenter (18) that produces alcohols by fermentation using the obtained
first sugar solution; a sulfuric acid decomposition device (33) that
decomposes, with sulfuric acid, the hemicellulose component in hot water
(30) discharged from the hydrothermal decomposition apparatus, which
contains the eluted lignin component and the eluted hemicellulose
component, so as to decompose the hemicellulose component to a second
sugar solution containing pentose; and a second alcohol fermenter (34)
that produces, using the second sugar solution containing pentose,
alcohols by fermentation.

Claims:

1. An organic material production system using biomass material, the
organic material production system comprising: a hydrothermal
decomposition apparatus that causes the biomass material and hot
compressed water to countercurrently contact with each other and undergo
hydrothermal decomposition, and that transfers a lignin component and a
hemicellulose component into the hot compressed water, so as to separate
the lignin component and the hemicellulose component from a biomass solid
residue; an enzymatic saccharification device that treats, with an
enzyme, cellulose in the biomass solid residue discharged from the
hydrothermal decomposition apparatus, so as to enzymatically saccharify
the cellulose to a first sugar solution containing hexose; a first
fermenter that produces, using the first sugar solution obtained by the
first enzymatic saccharification device, any one of alcohols, substitutes
for petroleum, or amino acids by fermentation; a sulfuric acid
decomposition device that decomposes, with sulfuric acid, the
hemicellulose component in hot water discharged from the hydrothermal
decomposition apparatus, so as to decompose the hemicellulose component
to a second sugar solution containing pentose; and a second fermenter
that produces, using the second sugar solution obtained by the sulfuric
acid decomposition device, any one of alcohols, substitutes for
petroleum, or amino acids by fermentation, wherein the hydrothermal
decomposition device has a reaction temperature ranging from 180.degree.
C. to 240.degree. C. and has a condition of hot compressed water.

2. (canceled)

3. The organic material production system according to claim 1, wherein
the sulfuric acid decomposition device has a decomposition temperature
ranging from 100.degree. C. to 140.degree. C.

4. A method for organic material production using biomass material, the
method comprising: a hydrothermal decomposition process that causes the
biomass material and hot compressed water to countercurrently contact
with each other and undergo hydrothermal decomposition; an enzymatic
saccharification process that treats, with an enzyme, cellulose in the
biomass solid residue discharged from the hydrothermal decomposition
process, so as to enzymatically saccharify the cellulose to a first sugar
solution containing hexose; a first fermentation process that produces,
using the first sugar solution obtained by the first enzymatic
saccharification process, any one of alcohols, substitutes for petroleum,
or amino acids by fermentation; a sulfuric acid decomposition process
that decomposes, with sulfuric acid, the hemicellulose component in hot
water discharged from the hydrothermal decomposition process, so as to
decompose the hemicellulose component to a second sugar solution
containing pentose; and a second fermentation process that produces,
using the second sugar solution obtained by the sulfuric acid
decomposition device, any one of alcohols, substitutes for petroleum, or
amino acids by fermentation, wherein a reaction temperature of the
hydrothermal decomposition ranges from 180.degree. C. to 240.degree. C.

5. (canceled)

6. The method for organic material production according to claim 4,
wherein the sulfuric acid decomposition process has a decomposition
temperature ranging from 100.degree. C. to 140.degree. C.

7. An organic material production system using biomass material, the
organic material production system comprising: a hydrothermal
decomposition apparatus that causes the biomass material and hot
compressed water to countercurrently contact with each other and undergo
hydrothermal decomposition, and that transfers a lignin component and a
hemicellulose component into the hot compressed water, so as to separate
the lignin component and the hemicellulose component from a biomass solid
residue; an enzymatic saccharification device that treats, with an
enzyme, cellulose in the biomass solid residue discharged from the
hydrothermal decomposition apparatus, so as to enzymatically saccharify
the cellulose to a first sugar solution containing hexose; and a sulfuric
acid decomposition device that decomposes, with sulfuric acid, the
hemicellulose component in hot water discharged from the hydrothermal
decomposition apparatus, so as to decompose the hemicellulose component
to a second sugar solution containing pentose; a second fermenter that
produces, using the second sugar solution obtained by the sulfuric acid
decomposition device, any one of alcohols, substitutes for petroleum, or
amino acids by fermentation, wherein the hydro thermal decomposition
device has a reaction temperature ranging from 180.degree. C. to
240.degree. C. and has a condition of hot compressed water.

8. The organic material production system according to claim 7 wherein
the sulfuric acid decomposition device has a decomposition temperature
ranging from 100.degree. C. to 140.degree. C.

9. A method for organic material production using biomass material, the
method comprising: a hydrothermal decomposition process that causes the
biomass material and hot compressed water to countercurrently contact
with each other and undergo hydrothermal decomposition; an enzymatic
saccharification process that treats, with an enzyme, cellulose in the
biomass solid residue discharged from the hydrothermal decomposition
process, so as to enzymatically saccharify the cellulose to a first sugar
solution containing hexose; and a sulfuric acid decomposition process
that decomposes, with sulfuric acid, the hemicellulose component in hot
water discharged from the hydrothermal decomposition process, so as to
decompose the hemicellulose component to a second sugar solution
containing pentose, wherein a reaction temperature of the hydrothermal
decomposition ranges from 180.degree. C. to 240.degree. C.

10. The method for organic material production according to claim 9,
wherein the sulfuric acid decomposition process has a decomposition
temperature ranging from 100.degree. C. to 140.degree. C.

Description:

TECHNICAL FIELD

[0001] The present invention relates to a biomass hydrothermal
decomposition apparatus and a method thereof that enable efficient
hydrothermal decomposition of biomass material, and to an organic
material production system using biomass material, which system enables
efficient production of organic materials such as alcohols, substitutes
for petroleum, or amino acids by using such apparatus and method.

BACKGROUND ART

[0002] Technologies for producing ethanol or the like have been
commercialized that involve converting woody biomass or other biomass
into sugars with dilute sulfuric acid or concentrated sulfuric acid, and
then subjecting them to solid-liquid separation, neutralizing the liquid
phase thereof, and utilizing the resultant components as biomass
materials for ethanol fermentation or the like (Patent Documents 1 and
2). Further, by using sugar as starting material, production of chemical
industrial raw material (e.g., lactic fermentation) has been considered.
Biomass as used herein refers to a living organism integrated in material
circulation in the global biosphere or accumulation of organic materials
derived from living organisms (see JIS K 3600 1258).

[0003] Sugarcane, corn, and other materials, currently used as alcohol raw
materials, have been originally used for food. Using such food resources
as long-term stable industrial resources is not preferable in view of
life cycle of valuable food.

[0004] For this reason, it is a challenge to efficiently use cellulose
resources such as herbaceous biomass and woody biomass, which are
considered as potentially useful resources.

[0005] Cellulose resources include cellulose ranging from 38% to 50%,
hemicelluloses components ranging from 23% to 32%, and lignin components,
which are not used as fermentation materials, ranging from 15% to 22%.
Due to many challenges, the industrial studies have been conducted
targeting certain fixed materials, and no technologies have been
disclosed yet on production systems taking into account diversity of the
materials.

[0006] Production systems targeting fixed materials see almost no point
regarding countermeasures for waste problems and global warming, because
those systems have attempted such countermeasures with a method that
brings more disadvantages to fermentation materials than starch
materials. Thus, there has been a need for a method applicable to a
variety of wastes in broader sense. Enzymatic saccharification methods
are also considered as a future challenge due to its low efficiency. Acid
treatment only achieves a low saccharification rate of about 75% (a basis
for components that can be saccharified), due to excessive decomposition
of sugar. Thus, the ethanol yield achieves only 25% by weight of
cellulose resources (Non-Patent Document 1 and Patent Document 3).

[0008] [Non-Patent Document 2] Biomass-Extensive Use of Bioresources,
edited by Japanese Society for Bioscience, Biotechnology, and
Agrochemistry, Asakura Publishing Co., Ltd., September 1985

DISCLOSURE OF INVENTION

Problem To Be Solved By The Invention

[0009] In the proposals disclosed in Patent Documents 1 and 2 above,
sulfuric acid necessary for reaction needs to be constantly supplied from
outside the reaction system. With increasing the production scale, this
poses problems, such as increasing the cost for purchasing equipment
resistant to the acid and large amounts of sulfuric acid, while
increasing the cost for disposing used sulfuric acid (e.g., cost for
processing with a gypsum desulfulation), and the cost for recovering such
sulfuric acid.

[0010] The proposal disclosed in Patent Document 3 above involves
subjecting various types of cellulose resources to hydrothermal
treatment, and converting them into sugars with enzymatic
saccharification. During the hydrothermal treatment, cellulase inhibitors
such as lignin components (Non-Patent Document 2) that inhibit enzymatic
saccharification of cellulose are not removed and mixed with cellulose.
This poses a problem of reducing the efficiency in cellulose enzymatic
saccharification.

[0011] Other than cellulose, hemicellulose components are also contained
in cellulose resources. This poses a problem that enzymes suitable for
cellulose and hemicellulose components are necessary for enzymatic
saccharification.

[0012] The resulting sugar solution includes a hexose solution from
cellulose, and a pentose solution from hemicellulose components. For
example, for alcohol fermentation, yeasts suitable for the respective
solutions are necessary. Thus, alcohol fermentation needs to be improved
low efficiency for fermenting a mixture of a hexose solution and a
pentose solution.

[0013] As such, conventional technologies have caused a phenomenon that
side reaction products inhibit enzymatic saccharification, reducing the
sugar yield. Thus, what has been needed is a hydrothermal decomposition
apparatus that removes inhibitors for enzymatic saccharification and
thereby improves enzymatic saccharification of cellulose-based
components.

[0014] In view of the foregoing problems, the present invention has an
object to provide an organic material production system using biomass
material, which can efficiently produce a sugar solution using such
apparatus and method, and can efficiently produce various types of
organic materials (e.g., alcohols, substitutes for petroleum, or amino
acids) using the sugar solution as a base material.

Means For Solving Problem

[0015] To achieve the above object, according to a first invention of the
present invention, an organic material production system using biomass
material includes: a hydrothermal decomposition apparatus that causes the
biomass material and hot compressed water to countercurrently contact
with each other and undergo hydrothermal decomposition, and that
transfers a lignin component and a hemicellulose component into the hot
compressed water, so as to separate the lignin component and the
hemicellulose component from a biomass solid residue; an enzymatic
saccharification device that treats, with an enzyme, cellulose in the
biomass solid residue discharged from the hydrothermal decomposition
apparatus, so as to enzymatically saccharify the cellulose to a first
sugar solution containing hexose; a first fermenter that produces, using
the first sugar solution obtained by the first enzymatic saccharification
device, any one of alcohols, substitutes for petroleum, or amino acids by
fermentation; a sulfuric acid decomposition device that decomposes, with
sulfuric acid, the hemicellulose component in hot water discharged from
the hydrothermal decomposition apparatus, so as to decompose the
hemicellulose component to a second sugar solution containing pentose;
and a second fermenter that produces, using the second sugar solution
obtained by the sulfuric acid decomposition device, any one of alcohols,
substitutes for petroleum, or amino acids by fermentation.

[0016] According to a second invention, in the organic material production
system according to the first invention, the hydrothermal decomposition
apparatus has a reaction temperature ranging from 180° C. to
240° C.

[0017] According to a third invention, in the organic material production
system according to the first or second inventions, the sulfuric acid
decomposition device has a decomposition temperature ranging from
100° C. to 140° C.

[0018] According to a forth invention, a method for organic material
production using biomass material includes: a hydrothermal decomposition
process that causes the biomass material and hot compressed water to
countercurrently contact with each other and undergo hydrothermal
decomposition; an enzymatic saccharification process that treats, with an
enzyme, cellulose in the biomass solid residue discharged from the
hydrothermal decomposition process, so as to enzymatically saccharify the
cellulose to a first sugar solution containing hexose; a first
fermentation process that produces, using the first sugar solution
obtained by the first enzymatic saccharification process, any one of
alcohols, substitutes for petroleum, or amino acids by fermentation; a
sulfuric acid decomposition process that decomposes, with sulfuric acid,
the hemicellulose component in hot water discharged from the hydrothermal
decomposition process, so as to decompose the hemicellulose component to
a second sugar solution containing pentose; and a second fermentation
process that produces, using the second sugar solution obtained by the
sulfuric acid decomposition device, any one of alcohols, substitutes for
petroleum, or amino acids by fermentation.

[0019] According to a fifth invention, in the method for organic material
production according to the forth invention, the hydrothermal
decomposition process has a reaction temperature ranging from 180°
C. to 240° C.

[0020] According to a sixth invention, in the method for organic material
production according to the forth or fifth inventions, the sulfuric acid
decomposition process has a decomposition temperature ranging from
100° C. to 140° C.

Effect Of The Invention

[0021] According to the present invention, with use of a hydrothermal
decomposition apparatus that causes counter-current contact, side
reaction products (lignin components and hemicellulose components)
resulting from the reaction for producing a target component, i.e.,
cellulose, (that is enzymatically saccharified to a hexose solution) are
transferred into the hot compressed water. In this way, the
cellulose-based biomass solid residue can be obtained. Accordingly, by
efficiently saccharifying it to the hexose solution and using the sugar
solution as a base material, various types of organic materials (e.g.,
alcohols, substitutes for petroleum, or amino acids) can be produced
efficiently. Further, the hemicellulose in the side reaction products,
transferred to the hot water, is converted with sulfuric acid to
monosaccharides at a low temperature, enabling liquid-liquid reaction
with good efficiency.

BRIEF DESCRIPTION OF DRAWINGS

[0022] [FIG. 1] FIG. 1 is a schematic of an alcohol production system
according to a first embodiment.

[0023] [FIG. 2] FIG. 2 is a schematic of a hydrothermal decomposition
apparatus according to a second embodiment.

[0024] [FIG. 3] FIG. 3 is a schematic of a hydrothermal decomposition
apparatus according to a third embodiment.

[0046] Exemplary embodiments of the present invention are described with
reference to the accompanying drawings. The present invention is not
limited to the embodiments. Constituting elements in the embodiments
include elements easily achieved by a person skilled in the art, or
elements being substantially equivalent to those elements.

First Embodiment

[0047] A system of producing an organic material, i.e., alcohol, with use
of biomass material according to an embodiment of the present invention
is described with reference to the drawings. FIG. 1 is a schematic of an
organic material production system using biomass material according to
the present embodiment. As shown in FIG. 1, an alcohol production system
10 using biomass material according to the present embodiment includes: a
hydrothermal decomposition apparatus 13 that causes a biomass material 11
and hot compressed water 12 to countercurrently contact with each other
and undergo hydrothermal decomposition, transfers lignin components and
hemicellulose components into the hot compressed water 12, and separates
the lignin components and the hemicellulose components from a biomass
solid residue; a cellulose enzymatic saccharification device 17 that
feeds an enzyme (cellulase) 15 into a biomass solid residue 14, which is
discharged from the hydrothermal decomposition apparatus 13, and treats
cellulose with the enzyme to enzymatically saccharify it to a first sugar
solution 16 containing hexose; a first alcohol fermenter 18 that
produces, using the first sugar solution (hexose) 16 obtained by the
cellulose enzymatic saccharification device 17, an alcohol (ethanol in
the present embodiment) by fermentation; a first refiner 22 that refines
a first alcohol fermentation liquid 19, obtained by the first alcohol
fermenter 18, so as to separate and refine it into a target product,
i.e., ethanol 20, and a first residue 21; a sulfuric acid decomposition
device 33 that discharges the hot compressed water 12, to which the
lignin components and the hemicellulose components are transferred in the
hydrothermal decomposition apparatus 13, as discharged hot water 30 to
the outside, feeds sulfuric acid 31 to the discharged hot water 30, and
decomposes with sulfuric acid the hemicellulose components in the
discharged hot water 30, so as to produce a second sugar solution 32
containing pentose; a second alcohol fermenter 34 that produces, using
the obtained second sugar solution (pentose) 32, an alcohol (ethanol in
the present embodiment) by fermentation; and a second refiner 37 that
refines a second alcohol fermentation liquid 35, so as to separate it
into the target product, i.e., ethanol 20, and a second residue 36.

[0048] Biomass to be fed to the hydrothermal decomposition apparatus 13 is
not limited to any specific type, and is a living organism integrated in
material circulation in global biosphere or accumulation of organic
materials derived from living organisms (see JIS K 3600 1258). In the
present invention, particularly, cellulose resources of wood materials
such as broadleaf trees and plant materials; agricultural wastes; and
food wastes are preferably used.

[0049] The biomass material 11 is preferably broken into particles having
a diameter of equal to or less than 5 millimeters for example, though not
limited to this particle diameter. In the present embodiment, the
pulverized biomass material 11 is used. Pretreatment equipment may be
provided as necessary that breaks the biomass material 11 into particles
having a diameter equal to or less than a predetermined diameter. When
the biomass material 11 is chaff for example, the biomass material 11 can
be fed to the hydrothermal decomposition apparatus 13 without being
subjected to pulverization. Examples of pretreatment equipment may
include cleaning equipment for cleaning biomass, as well as pulverizing
equipment for controlling the particle diameter.

[0050] In the hydrothermal decomposition apparatus 13, the reaction
temperature ranges from 180° C. to 240° C. preferably, and
from 200° C. to 230° C. more preferably. This is because,
at temperatures below 180° C., the hydrothermal decomposition
takes place at a low rate and requires a longer time, increasing the
apparatus size, which are not preferable. On the contrary, at
temperatures above 240° C., the decomposition rate is too high and
more cellulose components are transferred from the solid to the liquid,
facilitating excessive decomposition of hemicellulose sugars, which are
not preferable. Dissolution of cellulose components starts at about
140° C., dissolution of cellulose starts at about 230° C.,
and dissolution of lignin components starts at about 140° C. The
temperature is preferably set within a range from 180° C. to
240° C. that allows cellulose to be remained in the solid, and
that enables hemicellulose components and lignin components to be
decomposed at adequate rates.

[0051] The reaction pressure of the hydrothermal decomposition is
preferably set to a pressure higher by 0.1 MPa to 0.5 MPa than the
saturated steam pressure of water at each temperature, which allows the
hot compressed water to stay inside the device. The reaction time is
preferably three minutes to ten minutes, not more than 20 minutes. This
is because a longer reaction time increases the ratio of excessively
decomposed products and is not preferable.

[0052] According to the present invention, for the flowage of the hot
compressed water 15 and the flowage of the biomass material 11 inside the
device main body 42A of the hydrothermal decomposition apparatus 41-1A,
the hot compressed water 15 and the biomass material 11 are
countercurrently contacted.

[0053] In the hydrothermal decomposition apparatus 13, the solid of the
biomass material 11 is fed from the left side in the figure, while the
hot compressed water 12 is fed from the right side in the figure. Because
the biomass material 11 and the hot compressed water 12 move in an
opposite direction to one another, the hot compressed water 12 (hot
water, the liquid dissolving decomposed products) is moved while being
soaked in solid particles by the counter-current flow against the solid,
the biomass material 11.

[0054] When countercurrently contacting each other, the solid biomass
material 11 is decomposed with the hot compressed water 12, and the
resulting decomposed products are dissolved and transferred to the hot
compressed water 12.

[0055] As a ratio of the solid to the liquid, the liquid ratio is
preferably less, because it enables reduction in amount of water to be
recovered and in amount of steam used for warming during the hydrothermal
decomposition. The weight ratio of the biomass material and the hot
compressed water both to be fed is, for example, 1:1 to 1:10 preferably,
and 1:1 to 1:5 more preferably, though it varies accordingly depending on
the apparatus configuration.

[0056] According to the present invention, in the hydrothermal
decomposition apparatus 13, use of the counter-current flow transfers
lignin components and hemicellulose components to the liquid, i.e., the
hot compressed water 12, while allowing cellulose to remain in the solid,
i.e., the biomass solid residue 14, to be discharged from the
hydrothermal decomposition apparatus 13.

[0057] In this way, the first sugar solution (hexose) 16 is obtained at
the cellulose enzymatic saccharification device 17 for performing
enzymatic saccharification. Accordingly, it is possible to establish a
fermentation process suitable for a hexose (fermentation suitable for an
end product: in the present embodiment, the ethanol 20 is obtained by
fermentation using the first alcohol fermenter 18, and refined to the
first alcohol fermentation liquid 19).

[0058] According to the present invention, with use of a hydrothermal
decomposition apparatus that causes counter-current contact, side
reaction products (lignin components and hemicellulose components)
resulting from the reaction for producing a target component, i.e.,
cellulose, (that is enzymatically saccharified to a hexose solution) are
transferred into the hot compressed water. In this way, the
cellulose-based biomass solid residue can be obtained. Accordingly, by
efficiently saccharifying the cellulose and using the sugar solution as a
base material, various types of organic materials (e.g., alcohols) can be
produced efficiently.

[0059] In the present invention, by causing counter-current contact, their
components are sequentially discharged in order of solubility in the hot
compressed water 12. Further, due to the temperature gradient from where
the biomass is fed to where the hot water is fed, excessive decomposition
of hemicellulose components is prevented. As a result, pentose components
can be recovered efficiently. Further, by causing the biomass material
and the hot compressed water to countercurrently contact with each other,
the heat is recovered, which is preferable in view of system efficiency.

[0060] In the present embodiment, the ethanol 20 can be produced by
fermentation, using the second sugar solution (pentose) 32 obtained by
the sulfuric acid decomposition device 33.

[0061] As decomposition conditions in a sulfuric acid decomposition device
according to the present invention, a sulfuric acid concentration is 0.1%
by weight to 5% by weight, preferably 1% by weight to 4% by weight, a
decomposition temperature is 100° C. to 140° C., preferably
about 120° C., and a decomposition time is 30 minutes to three
hours, preferably about one hour. This is because conditions outside
these ranges result in unfavorable decomposition of hemicellulose.

[0062] In related art, when biomass material is decomposed with sulfuric
acid without undergoing pretreatment, decomposition is carried out using
sulfuric acid of 1% by weight for about 10 minutes at a high temperature
of about 180° C. Because sulfuric acid acts as an inhibitor
enzymatic saccharification of cellulose in downstream, the yield of
hexose is low.

[0063] According to the present invention, the hydrothermal decomposition
apparatus 13 causes cellulose components to remain in the biomass solid
residue 14 in advance, and treats hemicellulose components, transferred
to the hot compressed water 12, with sulfuric acid under a low
temperature condition. This arrangement simplifies the configuration of
the sulfuric acid equipment, and significantly reduces the use amount of
sulfuric acid (0.6 time to 0.9 time the use amount of sulfuric acid in
related art). As a result, the amount of sulfuric acid subjected to a
disposal process (gypsum desulfuration process) is reduced, so that the
equipment for recovering and separating sulfuric acid is downsized,
reducing the equipment size.

[0064] Because the decomposition using sulfuric acid takes place at a
temperatures equal to or less than 140° C., there is no need to
prepare equipment resistant to the acid for a high temperature
(180° C.) as in the related art, thus reducing the equipment cost.

[0065] When wheat straw was used as the biomass material 11 for example,
the yields of recovered sugars achieve 0.85 for pentose (recovery rate
85%), and 0.91 for hexose (recovery rate 91%), assuming one for each of
pentose and hexose in the wheat straw. As such, excellent recovery rates
were achieved.

[0066] The discharged hot water 30 is not necessarily treated in a
separate system. For example, processes subsequent to those performed at
the enzymatic saccharification device 17 and sulfuric acid decomposition
device 33, processes subsequent to those performed at the first and
second alcohol fermenters 18, 34, or processes subsequent to those
performed at the first and second refiners 22, 37 may be arranged as
common processes, or other modification may be made appropriately.

[0067] According to the present invention, in the hydrothermal
decomposition apparatus 13, use of the counter-current flow allows
cellulose to remain in the solid phase which is the biomass solid residue
14. Accordingly, the first sugar solution (hexose) 16 is obtained by the
enzymatic saccharification device 17 for performing enzymatic
saccharification. Further, hemicellulose components dissolved in the
liquid phase which is the hot compressed water 12, are separated as the
discharged hot water 30, and the second sugar solution (pentose) 32 is
obtained by the sulfuric acid decomposition device 33 using sulfuric
acid. This enables the first sugar solution and the second sugar solution
to be separated efficiently and saccharified in different processes.
Accordingly, fermentation processes suitable for each of hexose and
pentose (fermentation suitable for an end product: e.g., ethanol
fermentation) can be established.

[0068] As such, in the hydrothermal decomposition apparatus 13, use of the
counter-current flow transfers a side reaction product and a lignin
component soluble in hot compressed water, both acting as inhibitors
during enzymatic saccharification reaction for obtaining hexose, to the
hot compressed water 12. Accordingly, the cellulose-based biomass solid
residue 14 is obtained, improving the yield of the first sugar solution
16 containing pentose in the subsequent saccharification reaction by
enzyme.

[0069] On the other hand, hemicellulose components contained in the
separated discharged hot water 30 is saccharified later at the sulfuric
acid decomposition device 33, so that a second sugar solution 32
containing pentose can be obtained. Then, in the first and second alcohol
fermenters 18, 34 by using yeasts etc. suitable for hexose and pentose,
ethanol 20 can be obtained by fermentation individually and efficiently.

[0070] Although the present embodiment describes an example that an
alcohol, ethanol, is obtained by fermentation, the present invention is
not limited to this example. Other than alcohols, substitutes for
petroleum used as chemical product material, or amino acids used as food
and feed materials can be obtained with a fermenter.

[0072] As described above, the present invention provides: an organic
material production system and a method using biomass material that can
produce, by transferring cellulose-based components and hemicellulose
components from the biomass material to the hot compressed water and
separating them from each other, sugar solutions suitable for the
cellulose-based components and the himicellulose components (hexose sugar
solution and pentose sugar solution), and that can efficiently produce,
using the sugar solutions as base materials, various types of organic
materials (e.g., alcohols, substitutes for petroleum, or amino acids).
However, a conventional technology causes a phenomenon that a side
reaction product inhibits enzymatic saccharification and a sugar yield is
reduced.

Second Embodiment

[0073] With reference to the drawings, the following describes an
embodiment of a biomass thermal decomposition apparatus used in the
alcohol production system 10 using biomass material according to the
present invention. FIG. 2 is a schematic of a biomass hydrothermal
decomposition apparatus according to the embodiment. As shown in FIG. 2,
a biomass hydrothermal decomposition apparatus 13A according to the
present embodiment includes: a biomass feeder 40 that feeds a biomass
material 11 under normal pressure to under increased pressure; the
hydrothermal decomposition apparatus 13A that allows the fed biomass
material (e.g., wheat straw in the present embodiment) 11 to be gradually
conveyed inside a slanted device main body (hereinafter, "device main
body") 51 from a lower end thereof with a conveyor screw 52, and also
allows hot compressed water 12 to be fed into the device main body 51
from an upper end thereof, which is different from a feed section for the
biomass material 11, so as to cause the biomass material 11 and the hot
compressed water 12 to countercurrently contact with each other and
undergo hydrothermal decomposition, and that transfers lignin components
and hemicellulose components into the hot compressed water 12, so as to
separate the lignin components and the hemicellulose components from the
biomass material 11; and a biomass discharger 60 that discharges a
biomass solid residue 14 under increased pressure to under normal
pressure, at the upper end of the device main body 51. In the figure,
indicated by a reference numeral 53 is steam, 54 is a drain, and 55 is
pressurized nitrogen.

[0074] As such, with use of the slanted hydrothermal decomposition
apparatus 13A, the biomass material 11 and the hot compressed water 12
countercurrently contact with each other inside the apparatus.
Accordingly, side reaction products (lignin components and hemicellulose
components) resulting from the hydrothermal reaction for producing a
target component, i.e., cellulose, (that is enzymatically saccharified to
a hexose solution) are transferred into the hot compressed water 12. In
this way, the cellulose-based biomass solid residue 14 can be obtained.
Accordingly, by efficiently saccharifying the cellulose to the first
sugar solution containing hexose and using the sugar solution as a base
material, various types of organic materials (e.g., alcohols) can be
produced efficiently. On the other hand, the hemicellulose components in
the discharged hot water 30, discharged from the hydrothermal
decomposition apparatus 13A, are degraded by sulfuric acid decomposition
to a second sugar solution containing pentose and using the sugar
solution as a base material, various types of organic materials (e.g.,
alcohols) can be efficiently produced.

[0075] In the present embodiment, the biomass material 11 is fed from the
lower end. The present invention is not limited to this, and the biomass
material 11 may be fed from the upper end reversely. In this case, the
hot compressed water 12 is fed from the lower end. Examples of the
biomass feeder 40 that feeds biomass under normal pressure to under
increased pressure may include a pump unit such as a piston pump or a
slurry pump.

[0076] In the present embodiment, the hydrothermal decomposition apparatus
13A is a slanted type apparatus as shown in FIG. 2. The present invention
is not limited to this, and a vertical or horizontal hydrothermal
decomposition reaction apparatus may be adopted.

[0077] The hydrothermal decomposition apparatus may be arranged as a
slanted type or a vertical type, because it is preferable regarding that
the gas resulting from the hydrothermal decomposition reaction, the gas
brought into the material, and the like can be released quickly from the
upper side. This arrangement is also preferable in view of the
discharging efficiency, because decomposed products are discharged with
the hot compressed water 12 and therefore the concentration of the
discharged materials is increased from the upper side to the lower side.

[0078] According to a hydrothermal decomposition apparatus 13A of the
embodiment, by providing the conveyor screw 52, 1) the delivery of the
solid is possible by the counter-current flow of solid and liquid, 2) the
solid-liquid separation is possible inside the device main body 51, and
3) the hot compressed water on the surface of the solid and inside the
solid is progressively mixed inside the device main body 51, so that the
reaction is facilitated.

[0079] The conveyor screw 52 may include a scraper (not shown) that
prevents occlusion of an outlet for discharged hot water 30.

[0080] According to the present embodiment, in a slurry transport reactor
that mixes the biomass material 11 and water in advance and feeds the
mixture into the device main body, water needs to be added in large
amounts (10 times to 20 times in weight ratio) relative to the solid so
as to provide flowability to the slurry. However, because the material,
i.e., the biomass material 11, and the hot compressed water 12 for
removing lignin components and hemicelullose components in the biomass
are fed into the hydrothermal decomposition apparatus 13A with separate
systems, the weight ratio of the liquid can be made small relative to
that of the solid, thus improving economic efficiency.

[0081] According to the present invention, because a gas portion is
present inside the device main body 51, pressurized nitrogen (N2) 55
is fed inside.

[0082] Inside the hydrothermal decomposition apparatus 13A, the
temperature of the biomass material 11 is increased by causing it to
contact the hot compressed water 12 in the device main body 51 and
directly exchanging the heat. The temperature may be increased by using
steam or the like from the outside as necessary.

[0083] The biomass feeder 40 employs a screw feeding mechanism 41 that has
a material seal mechanism realized by the biomass itself, and feeds the
solid biomass material 11 under normal pressure to under increased
pressure. Specifically, with the feeding mechanism 41 including a screw
feeder 41a and a hydraulic cylinder 41b, the biomass material 11 fed
inside is compressed, so that a biomass plug 42 is formed. The biomass
plug 42 serves as a material seal for keeping the pressure inside the
hydrothermal decomposition apparatus 13A. Gradually pressed by the screw
feeder 41a, the biomass can be gradually discharged from an edge of the
hydraulic cylinder 41b, so that the biomass material 11 is reliably fed
into the device main body 51.

[0084] The biomass discharger 60 has a similar configuration to that of
the biomass feeder 40. With a feeding mechanism 61 including a screw
feeder 61a and a hydraulic cylinder 61b, the biomass solid residue 14
reacted in the hydrothermal decomposition apparatus is compressed, so
that a biomass plug 62 is formed. The biomass plug 62 serves as a
material seal for keeping the pressure inside the hydrothermal
decomposition apparatus 13A. The biomass solid residue 14 under increased
pressure, from which lignin components and hemicellulose components have
been transferred to the discharged hot water 30, can be discharged to
under normal pressure. When discharged, the residual water is removed
from the biomass plug 62. This dewatered solution 63 includes components
soluble in hot compressed water (lignin components and hemicellulose
components). Thus, the dewatered solution 63 is sent to the discharged
hot water 30 and treated together with the discharged hot water 30.

[0085] Because the pressure is changed from increased pressure to normal
pressure inside the biomass discharger 60, the discharged biomass solid
residue 14 is steam-exploded, causing breakage of its fiber. This
improves the efficiency of enzymatic saccharification in the subsequent
process.

[0086] The biomass discharger 60 can remove both of enzymatic
saccharification inhibitors and ethanol fermentation inhibitors, or
either of them, which are low-molecular-weight volatile inhibitors.

[0087] In the present invention, by causing biomass material and hot
compressed water to countercurrently contact with each other, their
components are sequentially eluted in order of solubility in the hot
water. Further, due to the temperature gradient from where the biomass is
fed to where the hot water is fed, excessive decomposition of
hemicellulose components is prevented. As a result, pentose components
can be recovered efficiently. Further, by causing the biomass material
and the hot compressed water to countercurrently contact with each other,
the heat is recovered, which is preferable in view of system efficiency.

Third Embodiment

[0088] With reference to the drawings, the following describes another
embodiment of the biomass hydrothermal decomposition apparatus used in
the alcohol production system 10 using biomass material according to the
present invention. FIG. 3 is a schematic of a biomass hydrothermal
decomposition apparatus according to the present embodiment. As shown in
FIG. 3, a biomass hydrothermal decomposition apparatus 13B according to
the present embodiment includes: a biomass feeder 80 that feeds the
biomass material (e.g., wheat straw in the present embodiment) 11 under
normal pressure to under increased pressure; a horizontal device main
body (hereinafter, "device main body") 70 that allows the fed biomass
material 11 to be gradually moved therethrough from an end on either the
left or the right side (on the left side in the present embodiment)
thereof in a consolidated condition, and also allows the hot compressed
water 12 to be fed therein from an end (on the right side in the present
embodiment), which is different from the side from which the biomass
material 11 is fed, so as to cause the biomass material 11 and the hot
compressed water 12 to countercurrently contact with each other and
undergo hydrothermal decomposition, and that transfers lignin components
and hemicellulose components into the hot compressed water 12, so as to
separate the lignin components and the hemicellulose components from the
biomass material 11; and the biomass discharger 60 that discharges the
biomass solid residue 14 under increased pressure to under normal
pressure, at the side from which the hot compressed water 12 is fed into
the device main body 70. Examples of the biomass feeder 80 that feeds
biomass under normal pressure to under increased pressure may include a
pump unit such as a piston pump or a slurry pump.

[0089] In the present embodiment, inside the device main body 70 is
provided a fixed stirring unit 71 that stirs the biomass material 11 in a
consolidated condition, so called in plug flow. With this arrangement,
the biomass material 11 fed therein is stirred by stirring action when
moved axially.

[0090] By providing the fixed stirring unit 71, the hot compressed water
12 on the surface of the solid and inside the solid is progressively
mixed in the device main body 70, so that the reaction is facilitated.

[0091] According to the present invention, for the flowage of the hot
compressed water 12 and the flowage of the biomass material 11 inside the
device main body 70 of the hydrothermal decomposition apparatus 13B, the
hot compressed water 12 and the biomass material 11 are countercurrently
contacted, preferably with agitated flow.

[0092] The hydrothermal decomposition apparatus 13B performs decomposition
in plug flow and has a simple configuration. Thus, the solid, the biomass
material 11 is moved parallel to a central axis of its pipe, while being
stirred in a direction perpendicular to the central axis of the pipe. On
the contrary, the hot compressed water 12 (hot water, the liquid
dissolving decomposed products) is moved while being soaked in solid
particles by the counter-current flow against the solid.

[0093] In the plug flow, the hot compressed water 12 is flowed uniformly.
This is because, when the solid biomass material 11 is decomposed in the
hot compressed water 12, the decomposed products are dissolved in the hot
water. Accordingly, the viscosity around a decomposed portion is
increased, so that the hot water is moved toward an undecomposed portion
dominantly, causing decomposition of the undecomposed portion. This
creates a uniform flow of the hot water, enabling uniform decomposition.

[0094] In the device main body 70 of the hydrothermal decomposition
apparatus 13B, due to the resistance of its inner pipe wall, the solid
density at the outlet side for the biomass material 11 is reduced
compared with that at the inlet side for the biomass material 11. In
addition, the amount of the biomass solid residue 14 is reduced by the
decomposition. As a result, the ratio of the hot compressed water 12 is
increased, and the liquid retention time is prolonged, causing excessive
decomposition of decomposed components in the liquid. For this reason,
the fixed stirring unit is provided as appropriate.

[0095] The fixed stirring unit 71 may have grooves formed thereon, or may
be installed at various pitches. Further, the fixed stirring unit 71 may
have screws in series at multiple stages, so that each screw performs
stirring individually. The device main body 70 of the hydrothermal
decomposition apparatus 13B may have a taper shape. Specifically, in the
device main body 70, the outlet for the biomass material 11 may have a
smaller cross-sectional area than the inlet. With this arrangement, the
solid density of the biomass material 11 is increased in the device main
body 70.

[0096] Further, an unstiffing function may be provided for preventing the
solid from occluding the device main body 70. Further, the solid-liquid
weight ratio in the device main body 70 may be controlled appropriately
by controlling, for example, the torque of a rotating stirring unit, the
capacitance and the ultrasonic wave in the device main body 70, and the
weight of components inside the device main body 70.

[0097] The hot compressed water 12 is flowed by the counter-current flow,
so that the heat is directly exchanged. This prevent excessive
decomposition of decomposed products (such as lignin components), which
are decomposed and discharged into the liquid phase.

[0098] The hot compressed water 12 to be fed into the device main body 70
is preferably less in weight relative to the biomass material 11, because
it enables reduction in amount of steam used for warming during the
hydrothermal decomposition. The weight ratio of the biomass material 11
to the hot compressed water 12 both to be fed is, for example, 1:1 to
1:10 preferably, and 1:1 to 1:5 more preferably, though it varies
accordingly depending on the apparatus configuration. Particularly, in
the present embodiment, the plug flow is composed of solid phase and
liquid phase, i.e. the biomass material and the hot compressed water, and
is moved through the device main body 70 in the consolidated condition.
The solid-to-liquid ratio can, therefore, be 1:1 to 1:5. As described,
the weight ratio of the biomass material 11 and the hot compressed water
12 both to be fed into the device main body 70 is made 1:1 to 1:10,
thereby reducing the heat necessary for the hydrothermal decomposition
apparatus.

[0099] Further, by controlling the solid-to-liquid weight ratio inside the
device main body 70, the conditions for hydrothermal decomposition are
stabilized, and the biomass solid residue 14 is stably discharged from
the biomass discharger 60.

[0100] By causing the biomass material 11 and the hot compressed water 12
to countercurrently contact with each other inside the hydrothermal
decomposition apparatus 13B, the solid-liquid separation is performed.
This reduces the amount of excessively decomposed products to be brought
into the solid, cellulose. Because lignin components and the like are
precipitated at low temperatures, the separation is difficult at low
temperatures. Thus, after the hydrothermal decomposition, the decomposed
products are taken out from the reaction system and subjected to the
separation. In this way, it is possible to reduce the heat loss when
flush occurs due to a transition from a high temperature and high
pressure condition to a normal temperature and normal pressure condition.
Further, the discharging liquid containing the decomposed products is
separated with improved efficiency. This arrangement is realized
considering the fact that the hydrothermal decomposition products are
polysaccharide components precipitated at low temperatures and therefore
the separation is hardly carried out at low temperatures.

[0101] According to the present embodiment, the weight of the biomass
material 11 to be fed into the hydrothermal decomposition apparatus 13B
is increased, relative to the weight of the hot compressed water 12. This
enables reduction in the apparatus size, thus contributing to improve
economic efficiency.

[0102] Inside the hydrothermal decomposition apparatus 13B, the
temperature of the biomass material 11 is increased by causing it to
contact the hot compressed water 12 in the device main body 70 and
directly exchanging the heat. The temperature may be increased by using
steam 53 or the like from the outside as necessary. Alternatively,
saturated steam may be directly fed into the device main body 42, instead
of the hot water.

[0103] In the present embodiment, the biomass feeder 80 employs a
mechanism for feeding the biomass material 11, including a piston pump
81a. With this arrangement, the biomass feeder 80 feeds the solid biomass
material 11 under normal pressure to under increased pressure. By using
the piston pump 81a and applying pressure with the piston, the biomass
material 11 is reliably fed into the device main body 70.

[0104] Specifically, use of the piston pump 81a enables the solid in the
counter-current flow of solid and liquid, i.e., the biomass material 11,
to be moved by operation of the piston pump 81a, without providing a
rotational moving unit or the like for moving the solid inside the device
main body 70. Further, use of the piston pump 81a also enables control of
the density inside the device main body 70 (the solid-to-liquid weight
ratio). Specifically, it is possible to control the retention time of the
hot compressed water inside the device main body 70.

[0105] The biomass discharger 60 is the same as that in the hydrothermal
decomposition apparatus 13A shown in FIG. 2, and thus descriptions
thereof are omitted.

[0106] In the present embodiment, the hot compressed water 12 is
discharged at a portion near the inlet for feeding the biomass.
Alternatively, a liquid outlet for the hot compressed water 12 may be
provided in a middle portion and the discharged liquid may be subjected
to both of heating and cooling, or either of them, so that an ideal
temperature distribution is plotted. Then, the discharged liquid may be
fed into the device main body 70 again.

[0107] The concentration of inhibitors such as furfral in the liquid may
be measured near a discharge section for the hot compressed water 12, so
that the feed amount of the hot compressed water 12 is controlled based
on the measured value. Or, the sugar concentration may be measured near
the biomass discharger 60, so that the feed amount of the hot compressed
water 12 is controlled based on the measured value.

[0108] In the present embodiment, the hot compressed water 12 may be fed
from one section. The present invention is not limited to this, and the
hot compressed water 12 may be fed from a plurality of sections for
temperature control.

[0109] In the present invention, by causing biomass material and hot
compressed water to countercurrently contact with each other, their
components are sequentially discharged in order of solubility in the hot
water. Further, due to the concentration gradient and the temperature
gradient from where the biomass is fed to where the hot water is fed,
excessive decomposition of hemicellulose components is prevented. As a
result, pentose components can be recovered efficiently. Further, by
causing the biomass material and the hot compressed water to
countercurrently contact with each other, the heat is recovered, which is
preferable in view of system efficiency.

[0110] According to a modification of the present embodiment, the
horizontal hydrothermal decomposition apparatus 13B as shown in FIG. 3
may be arranged as a slanted type or a vertical type. The device main
body may be arranged as a slanted type or a vertical type, because it is
preferable regarding that the gas resulting from the hydrothermal
decomposition reaction, the gas brought into the material, and the like
can be released quickly from the upper side. This arrangement is also
preferable in view of the discharging efficiency, because decomposed
products are discharged with the hot compressed water 12 and therefore
the concentration of the discharged materials is increased from the upper
side to the lower side.

Industrial Applicability

[0111] As described, the system and method according to the present
invention can separate cellulose-based components from biomass material,
so as to efficiently produce a sugar solution. Further, using the sugar
solution as a base material, various types of organic materials (e.g.,
alcohols, substitutes for petroleum, or amino acids) can be efficiently
produced.